John Constantine's new ride highlights the profound impact he has on the lives of those close to him, including his own son. Despite his best intentions, Constantine's choice of a Double-Decker bus is a symbolic gesture that further isolates his family and exacerbates the pain he has caused.
John Constantine usually travels through England with the help of Chas, but when he finds himself in America he decides to ride in style on a classic English Double-Decker bus.
When pressed on exactly why he chose such an absurd vehicle to travel in when there were so many better options, Constantine claims he can draw magic from it. But this excuse is swiftly torn apart by his companions. While John may claim that magic is the reason, the real reason is to make up for how he's hurt someone close to him.
It's usually very bad to be John Constantine's friend, it's even worse to be a member of his family. John's mother died during childbirth. His father was murdered by a serial killer after John, and his sister was killed and trapped in Hell. This doesn't even mention the numerous love interests whose lives have ended due to their connection with John Constantine. No one who considers John a loved one manages to escape unharmed for long. This is especially true of Noah. Because of John's manipulations, Noah had to murder someone, and now the police may be after him.
Because the police are likely looking for Noah for a murder he committed, there is no chance that he will ever return to England. His claim of pulling magic from the bus is a mere facade, used to buy him time and manipulate him into doing his bidding. John's actions reveal his deep-seated love for his son and his willingness to go to extreme lengths to protect him, even at the cost of honesty and respect.
As Constantine and his allies traverse America, the burden of his past actions weighs heavily upon him. Despite his intentions, his manipulation of his friends and the sacrifices he has made for them have left him with a profound sense of regret. While he may seek to atone for his past sins, his actions have consequences that transcend mere apologies.